Multi-layer insulation (MLI) blankets are useful in a number of applications. One application is insulating spacecraft. In this regard, remote sensing scientific spacecraft as well as commercial communications spacecraft require highly insulative MLI blankets to minimize undesirable heat intrusion and diurnal temperature swings. The insulative value of MLI blankets is generally determined by factors such as the overall number of layers included in the blanket, the extent of conductive shorting between adjacent layers, the quality of edge seams and closures, and the number and extent of penetrations through the blanket. However, these are not the only factors that can affect the insulative value of a MLI blanket.
The solar absorptance of the outer layer of a MLI blanket is also an important factor in determining the overall insulative value of the MLI blanket. In this regard, limited attention has been paid to the optical properties of the outer layer of MLI blankets, other than typically designing the blanket to achieve a high infrared emittance value of approximately 0.80. However, the solar absorptance of the outer layer, either after long-term contamination and ultraviolet (UV) degradation effects or due to inherent beginning-of-life (BOL) properties typically approaches the infrared emittance value, yielding an equivalent black body surface with steady-state temperatures of around 125° C. when directly illuminated with solar radiation in space.